[Coral-List] Sharpnose Puffer
allison.billiam at gmail.com
Sat Jan 3 10:32:32 EST 2009
I have seen in Maldives similar recruitment of C. striatus but the recruits
resembled a flashy A. lineatus (with more intense colours) and the adults,
although dark, are not black, and horizontal striations can be made out. I
documented abundance of these for several months after settlement during
which time attrition was rapid, especially in marginal habitat. I would like
to see a picture of the recruits you describe.
On Sat, Jan 3, 2009 at 1:49 AM, Douglas Fenner <dfenner at blueskynet.as>wrote:
> In American Samoa, there are mass recruitments in most years, particularly
> of the surgeonfish Ctenochaetus striatus, which is our most common adult
> reef fish. They seem to come in several pulses each year, and when they
> show up they are on the order of 4-5 cm long. The adults are black, but
> these new recruits have thin horizontal red lines on them. Then at some
> point later on, they all change to black. So you can tell when
> another recruitment pulse occurs, because suddenly you have more with red
> lines. There are quite a few of them that settle in most years, but in a
> few years spectacular numbers settle, huge schools of perhaps hundreds of
> thousands have been reported, and if they are in your transect, they can
> dominate the biomass not to mention number of individuals (Ali Green
> observed such schools here, including in her transects in 2002). After
> pulses, the numbers seem to go down steadily, but not really rapidly I
> say, Peter Craig here has data on that. If I remember, Ali Green saw in
> that huge pulse that many were in poor condition later, very thin, ragged
> fins, and so on (it's all in her report). I've not seen any like that in
> normal years, mind you I haven't studied it specifically.
> I'd recommend a paper on the survival of new recruits in Tahiti- if I
> remember, 60% were lost in the first 24 hours. They used a crest net to
> measure the recruitment each night, and daytime transects to record new
> recruits. They then subtracts to measure the mortality each 24 hr.
> References below.
> American Samoa has also had mass recruitments of two species of
> rabbitfish in recent years, even though the adults here are quite uncommon.
> We're not sure where they are coming from. They also recruit at roughly
> same size as the surgeons. There are also recruitment events of goatfish,
> and they are even larger, maybe around 10 cm or more when they settle.
> There is a
> traditional Samoan fishery for the newly settled goatfish, and a
> basket woven as a fish trap used to collect them. They have a name
> just for these goatfish recruits. So Samoans have known about them for a
> long time, possibly for nearly the 3000 years people have been here. They
> probably know a lot more useful information, too.
> And like many things on coral reefs, recruitment seems to be patchy in
> both space and time.
> -Doug Fenner
> Doherty, P. J., Dufour, V., Galzin, R. Hixon, M. A., Meekan, M. G., and S.
> Planes. 2004. High mortality during settlement is a population bottleneck
> for a tropical surgeonfish. Ecology 85: 2422-2428
> Almany, GR, Webster MS 2006. The predation gauntlet: early post-settlement
> mortality in reef fishes. Coral Reefs 25: 19-22
> Green, A. 2002. Status of the coral reefs on the main volcanic islands of
> American Samoa: a resurvey of long term monitoring sites (benthic
> communities, fish communities, and key macroinvertebrates). Report to
> Craig, P. 2005. Natural History Guide to American Samoa, 2nd Edition.
> National Park of American Samoa, Dept. Marine & Wildlife Resources, and
> American Samoa Community College, Pago Pago. 96 pages.
> ----- Original Message -----
> From: "John Ogden" <jogden at marine.usf.edu>
> To: "Will Welbourn" <will at bayislandsdiver.com>
> Cc: <Coral-List at coral.aoml.noaa.gov>
> Sent: Wednesday, December 31, 2008 4:49 AM
> Subject: Re: [Coral-List] Sharpnose Puffer
> > Hi Will,
> > My guess is that sharpnose puffers have the same type of recruitment as
> > Bill Gladfelter and I observed for balloonfish (Diodon holocanthus) many
> > years ago in St. Croix. The larvae are pelagic for a long larval life,
> > up to a year. During this interval; they slowly gather into huge
> > schools of many thousands of individuals (about 3cm long) which then
> > recruit en mass to whatever coastal region is favorable within the time
> > frame of development. The area then becomes completely flooded with
> > recruits which gradually disperse and are preyed upon. You could call
> > this a sort of 17-year locust type of recruitment.
> > It would be interesting to see if others have observed this type of
> > recruitment which may be more common than we know.
> > Happy New Year!
> > Will Welbourn wrote:
> >> Hello
> >> I was wanting to post about the huge population increase I have noted in
> >> the
> >> waters of Roatan Honduras. As a full time dive instructor here for the
> >> last
> >> five years the last six months I have observed an increase of 300-400%
> >> the abundance of this fish.
> >> Anyone know why or what it may indicate?
> >> Regards
> >> Will Welbourn, Course Director and Director of Roatan Marine Park
> >> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov
More information about the Coral-List